I liked this little walk through a book world:
When I was a little girl, I couldn't help feeling that there was something magically alive about books. That if one could only find the key, one could, like Gumby, slip inside a favorite title and live in its world. Though I suppose it would feel dreadfully Calvinist to live inside a book you'd already read. Everything would seem depressingly preordained. (I recall in Edgar Eager's Time Garden, when the children wrangled a trip into Little Women from the Natterjack, how relieved they were that Beth was home with a cold that day rather than out sledding with Jo and Laurie. They'd felt a bit queasy at the thought of meeting her, knowing that she dies in the second volume.
Or perhaps a book's characters might somehow slip into our world. I still recall a very old cartoon (Was it a Max Fleisher or a Warner Brothers?) which took place in a bookstore. During the night the book characters crept out and frolicked on the shelves. Seemed plausible to me.